Field of the Invention
The present invention relates to a backlight unit capable of alleviating a light leakage phenomenon and a liquid crystal display device including the same.
Discussion of the Related Art
In general, a liquid crystal display device is one of flat panel display devices, which displays images using a liquid crystal. The liquid crystal display device is widely used in various industrial fields in view of its advantages of thinness, lightness, low driving voltage, and low power consumption, when compared to other display devices.
Since a liquid crystal display panel for displaying images does not itself emit light, the liquid crystal display device uses a backlight unit including a light source for supplying light.
A light emitting diode (LED) is mainly used as a light source because the LED has the advantages of high response speed, excellent color reproducibility, and environmental-friendliness compared to a cold cathode fluorescent lamp (CCFL).
Recently, the liquid crystal display device is configured to form images on the liquid crystal display panel using a fluorescent film having quantum dots and white light generated from the LED. However, when the fluorescent film is cut corresponding to the size of the liquid crystal display panel, as shown in FIG. 1, a part of the quantum dot 10, which is located at an edge portion of the fluorescent film, is also cut off. Accordingly, the cross section of the quantum dot 10 is exposed from the lateral surface of the fluorescent film, and thus external moisture and oxygen permeate the exposed cross section of the quantum dot 10, and the properties of the quantum dot 10 are lost. The quantum dot 10, having lost its properties, cannot normally emit light having its own color. Further, the surface area of the quantum dot 10 that is cut in the fluorescent film cutting process becomes smaller than that of uncut quantum dots, and therefore the light incident on the fluorescent film from the LED cannot be properly converted into the color of the quantum dot 10.
Accordingly, some of the light incident on the edge region of the fluorescent film is projected through the edge region of the fluorescent film without mixing with the light converted by the quantum dot 10, which causes a light leakage phenomenon, whereby light having a specific wavelength leaks through the edge region of the fluorescent film. If the bezel is increased in size in order to prevent the light leakage phenomenon, the display area is decreased.